Added audio recording (#615)

app/MindWork AI Studio/Tools/MIME/TextBuilder.cs

@@ -0,0 +1,49 @@
+namespace AIStudio.Tools.MIME;
+
+public class TextBuilder : ISubtype
+{
+    private const BaseType BASE_TYPE = BaseType.TEXT;
+
+    private TextBuilder()
+    {
+    }
+
+    public static TextBuilder Create() => new();
+    
+    private TextSubtype subtype;
+
+    public TextBuilder UseSubtype(string subType)
+    {
+        this.subtype = subType.ToLowerInvariant() switch
+        {
+            "plain" => TextSubtype.PLAIN,
+            "html" => TextSubtype.HTML,
+            "css" => TextSubtype.CSS,
+            "csv" => TextSubtype.CSV,
+            "javascript" => TextSubtype.JAVASCRIPT,
+            "xml" => TextSubtype.XML,
+            "markdown" => TextSubtype.MARKDOWN,
+            "json" => TextSubtype.JSON,
+            
+            _ => throw new ArgumentException("Unsupported MIME text subtype.", nameof(subType))
+        };
+        
+        return this;
+    }
+
+    public TextBuilder UseSubtype(TextSubtype subType)
+    {
+        this.subtype = subType;
+        return this;
+    }
+    
+    #region Implementation of IMIMESubtype
+
+    public MIMEType Build() => new()
+    {
+        Type = this,
+        TextRepresentation = $"{BASE_TYPE}/{this.subtype}".ToLowerInvariant()
+    };
+
+    #endregion
+}